Method for producing hydrocarbons by Fischer-Tropsch process

ABSTRACT

A method for producing hydrocarbons, comprising: (I) subjecting to a reduction treatment a catalyst comprising a carrier having provided thereon: 0.1 to 10% by mass of at least one metal selected from an alkali metal, an alkaline earth metal, a rare earth metal and the Group III in the periodic table and 1 to 30% by mass of ruthenium, each based on the catalyst weight, the carrier comprising an aluminum oxide and a manganese oxide having an average number of charges of manganese of exceeding Mn 2+ , and the catalyst having a specific surface area of from 60 to 350 m 2 /g and a bulk density of from 0.8 to 1.8 g/ml; (II) dispersing the catalyst in liquid hydrocarbons in a concentration of from 1 to 50 w/v %; and (III) bringing the catalyst into contact with a gas mixture comprising hydrogen and carbon monoxide at a pressure of from 1 to 10 MPa, and (i) at a reaction temperature of from 170 to 300° C. under such conditions that carbon dioxide is substantially absent, or (ii) at a reaction temperature of from 200 to 350° C. under such conditions that carbon dioxide coexists in an amount of from 0.5 to 50% based on the total pressure of the hydrogen and the carbon monoxide.

TECHNICAL FIELD

The present invention relates to a method for producing hydrocarbonsfrom a gas mixture comprising hydrogen and carbon monoxide as maincomponents (hereinafter referred to as “synthesis gas”). Morespecifically, it relates to a method for producing hydrocarbons,particularly hydrocarbons rich in olefin components along with waxcomponents which can be easily converted into kerosine and gas oilfractions, comprising bringing the synthesis gas into contact with aruthenium catalyst using a carrier comprising an aluminum oxide and amanganese oxide which is dispersed in liquid hydrocarbons.

BACKGROUND ART

As methods for synthesizing hydrocarbons from the synthesis gas, aFischer-Tropsch reaction (hereinafter referred to as the “FT reaction”),a methanol synthesis method, a C₂-containing oxygen (ethanol,acetaldehyde) synthesis reaction and the like are well known. It isknown that the FT reaction proceeds by an iron system catalystcontaining iron, cobalt, ruthenium or the like, and the methanolsynthesis reaction proceeds by a copper system catalyst and theC₂-containing oxygen synthesis reaction proceeds by a rhodium systemcatalyst, and it is known that the catalytic ability of catalysts to beused in the synthesis of the hydrocarbons is strongly related to thedissociative adsorption ability of carbon monoxide (e.g., HomogeneousCatalysts and Heterogeneous Catalysts, edited by Hidai and Ichikawa,published by Maruzen, 1983).

On the other hand, low sulfur content gas oil is in demand in recentyears from the viewpoint of atmospheric environmental protection, and itis considered that this tendency will become stronger in the future.Also, since crude oil is limited, development of an energy source thatreplaces the oil is in demand, and it is considered that this demandwill become stronger in the future. As a technique that meets thesedemands, so-called GTL (gas to liquid) is known as a technique forsynthesizing liquid fuels such as kerosine and gas oils from natural gas(main component: methane) which is considered to have recoverablereserves equivalent to crude oil on energy conversion basis. Sincenatural gas contains no sulfur components, or if contained, they arehydrogen sulfide (H₂S), mercaptan (CH₃SH) and the like which can beeasily desulfurized, the thus obtained liquid fuels kerosine and gasoils and the like hardly contain sulfur components therein and they haveadvantages in that, e.g., they can be applied to high performance dieselfuel having a high cetane number, so that the GTL has been drawingattention more and more in recent years.

As a part of the GTL, a method for producing hydrocarbons from asynthesis gas by the FT reaction is being studied actively. In order toincrease the yield of kerosine and gas oil fractions in producinghydrocarbons by the FT method, it is important to synthesizehydrocarbons equivalent to C₁₀ to C₁₆ hydrocarbons efficiently. Ingeneral, it is said that the distribution of carbon numbers ofhydrocarbon products by the FT reaction follows the Shultz-Flory rule,and it is considered that, according to the Shultz-Flory rule, the chainpropagation probability (α) value has a tendency to greatly decreasewith increase in the reaction temperature, namely a tendency that thenumber of carbons of formed hydrocarbons is greatly reduced when thereaction temperature is increased. It seems that technical developmentssuch as catalyst development and the like had been positively carriedout formerly with the aim of selectively synthesizing hydrocarbonshaving a specified number of carbons by excluding the Shultz-Flory rule,but a technique which sufficiently resolved this problem has not beenproposed yet. Rather, it is a recent idea that the yield of fractionswhich can be easily made into kerosine and gas oil fractions byhydro-cracking of wax components and the like is increased, not stickingto the exclusion of Shultz-Flory rule, and the wax components and thelike are subjected to hydro-cracking to increase the yield of kerosineand gas oil fractions as the result. However, since the chainpropagation probability (α) at the present time is around 0.85, it isone of the recent technical problems how to increase the value.Nevertheless, since the wax components become the majority of the formedhydrocarbons when the chain propagation probability (α) is increased toohigh, a problem on the process operation is generated instead so that,also from the viewpoint of general properties of the catalyst, it isconsidered that around 0.95 is the actual upper limit of the chainpropagation probability (α).

Accordingly, in order to increase the yield of the kerosine and gas oilfractions further, it is necessary to consider formation of kerosine andgas oil fractions by forming lower olefin and carrying out itsdimerization, trimerization and the like, in addition to the improvementof kerosine and gas oil fractions by forming wax components and carryingout the hydro-cracking. It is considered that such a still moreimprovement of the yield of kerosine and gas oil fractions can beachieved by carrying out the FT reaction which has high chainpropagation probability (α), is excellent in the olefin selectivity inthe formed lower hydrocarbon and is also excellent in the productivityof a liquid hydrocarbon fraction having a carbon number of 5 or more(hereinafter referred to as “C₅+”).

Also, regarding the synthesis gas which is the material of theproduction of hydrocarbons by the FT method in the GTL process, thesynthesis gas is mainly obtained by reforming a natural gas into a gasmixture comprising hydrogen and carbon monoxide as main components, by areforming method such as autothermal reforming or steam reforming.However, since a water gas shift reaction of the following equation (II)occurs by this reforming in parallel with a reforming reaction of thefollowing equation (I), carbon dioxide gas is inevitably contained inthe thus obtained synthesis gas. In addition, since unused natural gasfields contain carbon dioxide gas in many cases, the use of such acarbon dioxide gas-containing natural gas as the material results inlarger carbon dioxide gas content in the thus obtained synthesis gas.CH₄+H₂O=3H₂+CO  (I)CO+H₂O=H₂+CO₂  (II)

Also, as shown by the following equation (III), a liquid hydrocarbon issynthesized from the synthesis gas by the FT reaction, a tendency ofobstructing synthesis of the hydrocarbon becomes strong when carbondioxide gas is contained in the reaction system (Suzuki et al., Abstractof Papers, the 63rd Spring Annual Meeting of The Chemical Society ofJapan, 3C432, 1992). Also, when the carbon dioxide gas content isincreased, a hydrogen partial pressure in the reaction system isdecreased in addition to the reaction inhibition of carbon dioxide gas,so that it becomes an undesirable situation for the FT reaction fromthis point, too.nCO+2nH₂=(CH₂)_(n) +nH₂O  (III)

Accordingly, it becomes essential for the conventional GTL process toincorporate a decarbondioxide step for removing carbon dioxide gas inthe synthesis gas, between a step for producing a synthesis gas from anatural gas and a step for synthesizing a liquid hydrocarbon from thesynthesis gas. Generally, amine absorption or pressure swing adsorption(PSA) is used in the decarbondioxide step, but such a decarbondioxidestep is not desirable in any case, because it causes rise inconstruction cost and operation cost. When the decarbondioxide step canbe simplified or omitted by enabling the FT reaction suitably in thecoexistence of carbon dioxide gas, it can be greatly contributed to thereduction of production cost of the liquid hydrocarbon in the GTLprocess.

However, neither catalyst nor process, by which the FT reaction havinghigh chain propagation probability (α) and excellent olefin selectivityand C₅+ productivity and capable of sufficiently achieving further moreimprovement of the yield of kerosine and gas oil fractions can becarried out, has been proposed yet. Various catalysts for the FTreaction have been proposed, and a ruthenium catalyst comprising amanganese oxide carrier having provided thereon ruthenium, a rutheniumseries catalyst in which a third component was added to the rutheniumcatalyst, and the like have been proposed as catalysts for highselectivity for olefins (JP-B-3-70691, JP-B-3-70692, and the like).However, further more improvement of the yield of kerosine and gas oilfractions cannot be achieved sufficiently by the FT method using theruthenium series catalysts. That is, since the ruthenium seriescatalysts are developed with the aim of using them in a fixed-bedsystem, the fixed-bed FT method using the ruthenium series catalysts hasa problem in that the reaction cannot be carried out stably andsmoothly, because not only insufficient chain propagation probability(α) and the like of the ruthenium series catalysts, but also thefixed-bed reaction system is apt to cause reduction of the catalyticactivity when wax components are formed in a large amount, due toaccumulation of the formed wax components to the active site of thecatalyst and subsequent covering of the site, as well as its aptness togenerate heat spots when the catalyst bed is topically overheated.

What is more, as described above, neither catalyst nor process, by whichthe FT reaction having high chain propagation probability (α) andexcellent olefin selectivity and C₅+ productivity and capable ofsufficiently achieving further more improvement of the yield of kerosineand gas oil fractions can be carried out in the coexistence of carbondioxide gas, has been proposed yet.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide the FT method which hashigh chain propagation probability (α), is excellent in olefinselectivity and C₅+ productivity, has high catalytic activity, canperform the reaction stably and smoothly without generating heat spotsand can carry out the desired reaction in the optional coexistence ofcarbon dioxide gas.

Another object is to provide the FT method which can contribute to theincreased production of kerosine and gas oil fractions further moregreatly than conventional methods, by hydro-cracking of the formed waxcomponents and dimerization, trimerization and the like of the formedolefin, and also can contribute greatly to the reduction of productioncost of kerosine and gas oil fractions by simplifying or omitting thedecarbondioxide step for removing carbon dioxide gas in the synthesisgas.

The present invention relates to a method for producing hydrocarbons,comprising:

-   (I) subjecting to a reduction treatment a catalyst comprising a    carrier having provided thereon:    -   0.1 to 10% by mass of at least one metal selected from an alkali        metal, an alkaline earth metal, a rare earth metal and the Group        III in the periodic table based on the catalyst weight, and    -   1 to 30% by mass of ruthenium based on the catalyst weight,    -   said carrier comprising an aluminum oxide and a manganese oxide        having an average number of charges of manganese of exceeding        Mn²⁺, and    -   said catalyst having a specific surface area of from 60 to 350        m²/g and a bulk density of from 0.8 to 1.8 g/ml;-   (II) dispersing the catalyst in liquid hydrocarbons in a    concentration of from 1 to 50 w/v %; and-   (III) bringing the catalyst into contact with a gas mixture    comprising hydrogen and carbon monoxide at a pressure of from 1 to    10 MPa, and    -   (i) at a reaction temperature of from 170 to 300° C. under such        conditions that carbon dioxide is substantially absent, or    -   (ii) at a reaction temperature of from 200 to 350° C. under such        conditions that carbon dioxide coexists in an amount of from 0.5        to 50% based on the total pressure of the hydrogen and the        carbon monoxide.

BEST MODE FOR CARRYING OUT THE INVENTION

In order to achieve the above objects, the present inventors haveconducted intensive studies and found as a result that the FT method canbe carried out stably and smoothly with high chain propagationprobability (α), excellent olefin selectivity and C₅+ productivity andhigh catalytic activity without generating heat spots and the like,under such conditions either that carbon dioxide gas (carbon dioxide) issubstantially absent or that carbon dioxide coexists, by using, as acatalyst, one comprising a carrier having provided thereon predeterminedamounts of a specific metal such as an alkali metal and ruthenium,wherein the carrier comprises an aluminum oxide and a certain manganeseoxide and wherein the catalyst has a relatively large predeterminedspecific surface area and a relatively small predetermined bulk density,and by subjecting the catalyst to reduction treatment in advance,dispersing the catalyst in liquid hydrocarbons at a predeterminedconcentration, and then bringing the dispersed catalyst into contactwith a material synthesis gas, so that the above objects can beachieved. Also, the present inventors had found that the FT reactionrate is further enhanced and the conversion ratio of carbon monoxide isfurther improved when the reaction is carried out in the coexistence ofa predetermined amount of carbon dioxide, and the present invention hasbeen accomplished based on these findings.

According to the present invention, reduction of the catalytic activitycaused by the accumulation of wax components to the catalytic activesite can be prevented even when the amount of the wax components in thereaction mixture becomes large, and the reaction can be carried outstably and smoothly by inhibiting generation of heat spots and the like,because of the specific reaction system described above in which thedispersed catalyst in liquid hydrocarbons at a predeterminedconcentration is brought into react with the material synthesis gas.Also, the catalyst having the specified composition and physicalproperties described above is most suitable for the specific reactionsystem described above, can realize the FT reaction having high chainpropagation probability (α) and excellent olefin selectivity and C₅+productivity, and can realize the suitable FT reaction under suchconditions either that carbon dioxide is substantially absent or that apredetermined amount of carbon dioxide coexists. Also, the reaction inthe coexistence of a predetermined amount of carbon dioxide ispreferable since the FT reaction rate is further enhanced and theconversion ratio of carbon monoxide is further improved.

In general, it is considered that reduction of the bulk density ofcatalyst is effective for improving productivity of the substance ofinterest per catalyst weight, but the objects of the present inventioncannot be achieved by simply reducing the bulk density of the catalyst.That is, as will be described later in Comparative Example 6 forexample, a conventionally known catalyst comprising an alumina carrierhaving a small bulk density and having provided thereon sodium andruthenium shows low C₅+ productivity, and its chain propagationprobability (α) and olefin selectivity are also low, so that the objectsof the present invention cannot be achieved. On the other hand, in thecatalyst used in the present invention which comprises a carrier havingprovided thereon a metal such as an alkali metal and ruthenium, whereinthe carrier comprises an aluminum oxide and a certain manganese oxide,the C₅+ productivity can be increased by limiting its bulk densitywithin a relatively small range, and its high chain propagationprobability (α) and olefin selectivity can also be obtained, so that theabove object can be achieved.

The present invention will be explained below in more detail.

According to the method of the present invention, as a catalyst, used isone comprising a carrier having provided thereon at least one metalselected from the group consisting of an alkali metal, an alkaline earthmetal, a rare earth metal and the Group III in the periodic table andruthenium, wherein the carrier comprises an aluminum oxide and amanganese oxide having an average number of charges of manganese ofexceeding Mn²⁺, and wherein amounts of the metal and ruthenium and itsphysical properties including a specific surface area and a bulk densityare within the following predetermined ranges.

As the aluminum oxide which is one component of the carrier of thecatalyst used in the present invention, neutral alumina or aluminashowing base property is preferably used in order to obtain high chainpropagation probability (α) and stable reaction activity. When acidicalumina is used, it is necessary to take care because of a possibilityof reducing the chain propagation probability (α) and reducing thereaction activity. As the manganese oxide which is the other componentof the carrier, a manganese oxide having an average number of charges ofmanganese of exceeding Mn²⁺ is used. For example, as described in theU.S. Pat. No. 4,206,134, a manganese oxide having an average number ofcharges of manganese of Mn²+ or less is suitable for the formation ofolefin of gaseous hydrocarbon (C₂ to C₄), but is not suitable for theproduction of liquid hydrocarbons which are the objects of the presentinvention. Preferred examples of the manganese oxide having an averagenumber of charges of manganese of exceeding Mn²⁺ include MnO₂, Mn₂O₃,Mn₃O₄ and the like. In addition, a manganese oxide having an averagenumber of charges of manganese of exceeding Mn²⁺ obtained from saltother than oxide such as manganese nitrate or the like as the startingmaterial can also be used. For example, Mn₂O₃ and the like obtained byburning manganese nitrate in the air can be preferably used. A ratio ofthe aluminum oxide and the manganese oxide on the carrier is generallyfrom 5 to 160 mass parts, preferably from 10 to 110 mass parts, of themanganese oxide based on 100 mass parts of the aluminum oxide. When theratio of the manganese oxide is less than 5 mass parts, interaction ofthe manganese oxide with the metal and ruthenium is reduced and each ofthe chain propagation probability (α), C₅+ selectivity andolefin/paraffin ratio is reduced, thus having a possibility of being notsuitable for the production of a liquid hydrocarbon. When it exceeds 160mass parts, on the other hand, there is a possibility that the bulkdensity or specific surface area of the catalyst cannot satisfy thepreferred range. Also, the carrier can be prepared in accordance with ausual method and can be carried out by mixing and burning an aluminumoxide material and a manganese oxide material at a predetermined ratio.In addition, the carrier may be any shape such as powder, granule,tablet molding, extrusion molding and the like.

Also, in the catalyst used in the present invention, amounts of themetal and ruthenium are related to the number of active sites. An amountof the metal in the catalyst used in the present invention is from 0.1to 10% by mass, preferably from 0.2 to 7% by mass, and more preferablyfrom 0.2 to 3% by mass, based on the catalyst weight. Also, the amountof ruthenium is from 1 to 30% by mass, preferably from 1 to 20% by mass,and more preferably from 1.5 to 10% by mass, based on the catalystweight. When the amount of each of the metal and ruthenium is less thanthe above range, not only there is a possibility that sufficientcatalytic activity cannot be obtained due to insufficient number ofactive sites, but also synergistic effect of the metal, ruthenium andthe like with the carrier components (aluminum and manganese) cannot beobtained, thus entailing lack in deterioration gradient and catalyststability (life span). Also, when the amount of each of the metal andruthenium exceeds the above range, the metal and ruthenium cannotsufficiently be provided on the carrier, their dispersion is reduced,and a metal species and a ruthenium species which do not haveinteraction with the carrier components, are generated, thus causing anundesirable tendency of considerably reducing the activity andselectivity. Also, the chemical composition of the catalyst wascalculated by an inductively coupled plasma mass spectrometry (ICPmethod).

A specific surface area of the catalyst used in the present invention isfrom 60 to 350 m²/g, preferably from 80 to 300 m²/g, and more preferablyfrom 100 to 250 m²/g. A specific surface area of less than 60 m²/g isnot preferable because of a possibility of reducing dispersion of themetal and the ruthenium. Also, regarding the upper limit of the specificsurface area, larger specific surface areas are preferable generally inhandling a solid catalyst, because the gas-liquid-solid contactingfrequency is increased. However, when taken into consideration that thepractical upper limit of the specific surface area of the carriercontaining the aluminum oxide and manganese oxide used in the presentinvention is approximately from 350 to 380 m²/g, it is considered thatthis area of the catalyst comprising the metal and ruthenium isapproximately 350 m²/g at the most. Also, the specific surface area ofthe catalyst was calculated by BET method (Braunauer-Emett-Tailormethod) using high purity nitrogen as the probe.

Also, a bulk density of the catalyst used in the present invention isfrom 0.8 to 1.8 g/ml, preferably from 0.9 to 1.5 g/ml, and morepreferably from 0.9 to 1.3 g/ml. However, when taken into considerationthat the practical lower limit of the bulk density of the carriercomprising the aluminum oxide and the manganese oxide used in thepresent invention is approximately 0.7 g/ml, it is considered that thevalue of the catalyst comprising the metal and ruthenium isapproximately 0.8 g/ml at the most. On the other hand, when the bulkdensity exceeds 1.8 g/ml, the C₅+ productivity per catalyst weightbecomes low entailing a possibility of being not suitable of theproduction of a liquid hydrocarbon.

Also, the catalyst used in the present invention has a catalyst particlesize distribution range of from 5 to 200 μm, preferably from 5 to 180μm, and more preferably from 10 to 150 μm. Since the catalyst of thepresent invention is used in a dispersed state by dispersing it inliquid hydrocarbons, it is preferable to take its particle sizedistribution into consideration. Fine particles of less than 5 μm have ahigh possibility of generating problems in that they are passed througha filter or the like and leaked into the downstream side to causereduction of the catalyst concentration inside the reaction vessel, andan apparatus of the downstream side is damaged by the catalyst fineparticles. Also, large particles of exceeding 200 μm have a highpossibility of reducing the reaction activity because of a difficulty inuniformly dispersing them in liquid hydrocarbons throughout the entirereaction vessel and due to the formation of irregular slurry in whichthe catalyst is dispersed.

Even when the particle size distribution is within the above range offrom 5 to 200 μm, there is a case in which irregular dispersion occurswhen they are dispersed in liquid hydrocarbons. In that case, it ispreferable to take an average particle size into consideration foruniformly dispersing the catalyst particles in liquid hydrocarbonswithout generating irregularity. An average particle size of thecatalyst used in the present invention is preferably from 20 to 100 μm,more preferably from 25 to 100 μm, and most preferably from 25 to 80 μm.When the average particle size is outside the upper and lower limits ofthe range of from 20 to 100 μm, dispersion of the catalyst particles inliquid hydrocarbons may become irregular to cause reduction of thereaction activity.

Regarding preparation of the catalyst used in the present invention, thepreparation method by itself can be carried out in accordance with aconventionally known general preparation method of catalysts. Inproviding the carrier comprising an aluminum oxide and a manganese oxidewith the metal and ruthenium, the metal is firstly provided thereon andthen burned after removing moisture. Next, the ruthenium is providedthereon and then thoroughly dried after removing moisture. Also, themetal or ruthenium can be provided on the carrier by bringing thecarrier into contact with a solution of a catalyst species compound,e.g., by soaking the carrier in a solution of a catalyst speciescompound such as a compound of the metal or a ruthenium compound, andaccumulating the catalyst species compound on the carrier, adhering thecatalyst species compound by ion exchange, precipitating the catalystspecies compound by adding a precipitant such as an alkali or the like,evaporating the solution to dryness or adding the solution of thecatalyst species compound onto the carrier dropwise. In this case, inorder to control amounts of the metal and ruthenium in the thus obtainedcatalyst of interest, amounts of these catalyst species compounds to becontained in the carrier is adjusted. Examples of the compound of themetal provided on the carrier include chlorides, carbonates, nitrates,ammonia salts and the like of sodium, potassium, lithium, beryllium,barium, magnesium, cerium, calcium, yttrium and the like. Among these,compounds of sodium, potassium, calcium and the like are preferablyused. The compounds of a certain metal including an alkali metal can beused alone or as a mixture of two or more. Also, as the rutheniumcompound, various ruthenium compounds conventionally used in thepreparation of ruthenium-provided catalysts can be used by optionallyselecting them. Preferred examples include water-soluble ruthenium saltssuch as ruthenium chloride, ruthenium nitrate, ruthenium acetate,ruthenium hexachloroammonium chloride and the like and organicsolvent-soluble ruthenium compounds such as ruthenium carbonyl,ruthenium acetylacetonate and the like. The carrier in which the metaland ruthenium are contained in the above manner is dried. Drying can becarried out generally by keeping it at from ordinary temperature to 300°C. for 10 to 48 hours. The thus dried carrier containing respectivecatalyst species is optionally pulverized and classified, if necessary,to obtain a desired catalyst particle size distribution and further madeinto a state of powder having a desired average particle size asoccasion demands, so that a catalyst used in the present inventionhaving predetermined various physical properties can be obtained.

According to the method of the present invention for producinghydrocarbons, the catalyst prepared in the above manner is subjected toa reduction treatment (activation treatment) in advance prior tosubjecting to the FT reaction. By the reduction treatment, the catalystis activated so that it shows the desired catalytic activity in the FTreaction. When the reduction treatment is not carried out, the metal andruthenium provided on the carrier are not sufficiently reduced and donot show the desired catalytic activity for the FT reaction. Thereduction treatment can be preferably carried out either by a method inwhich the catalyst in a state of slurry prepared by dispersing it inliquid hydrocarbons is brought into contact with a reducing gas or amethod in which a reducing gas is simply brought into contact with thecatalyst by blowing it without using hydrocarbons. As the liquidhydrocarbons for dispersing the catalyst in the former method, varioushydrocarbons including olefins, alkanes, alicyclic hydrocarbons andaromatic hydrocarbons can be used, so long as they are liquids under thetreating conditions. Also, it may be a hetero atom-containinghydrocarbon such as oxygen-containing, nitrogen-containing hydrocarbonsor the like. The number of carbons of the hydrocarbons is notparticularly limited, so long as they are liquids under the treatingconditions, but generally, those of C₆ to C₄₀ are preferable, those ofC₉ to C₄₀ are more preferable, and those of C₉ to C₃₅ are mostpreferable. In hydrocarbons lighter than C₆, the vapor pressure of thesolvent becomes high so that the range of their treating condition islimited. Also, in hydrocarbons heavier than C₄₀, the solubility of thereducing gas is reduced which causes a possibility that sufficientreduction treatment becomes impossible. Moreover, an amount of thecatalyst dispersed in hydrocarbons is suitably a concentration of from 1to 50 w/v %, preferably from 3 to 40 w/v %, and more preferably from 5to 35 w/v %. When the amount of catalyst is less than 1% by mass,reducing efficiency of the catalyst is decreased. Although there is amethod to reduce quantity of gas flow of the reducing gas as a methodfor preventing decrease in the reducing efficiency of the catalyst, thisis not preferable because the gas (reducing gas)-liquid (solvent)-solid(catalyst) dispersion is inhibited when the quantity of gas flow of thereducing gas is reduced. On the other hand, a large amount of thecatalyst exceeding 50% by mass is not preferable because the viscosityof the slurry prepared by dispersing the catalyst in hydrocarbonsbecomes so high that dispersion of bubbles becomes poor and reduction ofthe catalyst cannot be made sufficiently. The reduction treatmenttemperature is preferably from 140 to 310° C., more preferably from 150to 250° C., and most preferably from 160 to 220° C. When it is less than140° C., ruthenium is not sufficiently reduced so that sufficientreaction activity cannot be obtained. Also, when it is a hightemperature exceeding 310° C., changes in the phase transition andoxidation conditions of the manganese oxide and the like in the carrierare advanced to form a complex with ruthenium, thereby causing sinteringof the catalyst so that a possibility of causing reduction of theactivity becomes high. In the reduction treatment, a reducing gascontaining hydrogen as the main component can be used preferably. Thereducing gas used may contain a component other than hydrogen, such aswater vapor, nitrogen, rare gas and the like, in a certain amount, solong as the reduction is not inhibited. The reduction treatment isinfluenced by the hydrogen partial pressure and treating time togetherwith the above treating temperature, and the hydrogen partial pressureis preferably from 0.1 to 10 MPa, more preferably from 0.5 to 6 MPa, andmost preferably from 1 to 5 MPa. The reduction treatment time variesdepending on the amount of catalyst, rate of hydrogen flow and the like,but in general, is preferably from 0.1 to 72 hours, more preferably from1 to 48 hours, and most preferably from 4 to 48 hours. When the treatingtime is less than 0.1 hour, activation of the catalyst becomesinsufficient. Also, when the reduction treatment is carried out for aprolonged period of time exceeding 72 hours, there is no bad influenceupon the catalyst, but it causes an undesirable problem such as hightreatment cost while improvement of the catalyst performance cannot beobtained.

It is preferable that the catalyst after the reduction treatment shows acertain range of ruthenium dispersion. That is, in general, thedispersion of ruthenium means a percentage of the adsorbed carbonmonoxide (CO) mole numbers of the catalyst after reduction treatmentbased on the ruthenium mole numbers in the catalyst, and is defined bythe following formula.${{Ru}\quad{dispersion}} = {\frac{{Adsorbed}\quad{CO}\quad{mol}\quad{numbers}\quad{of}\quad{catalyst}}{{Ru}\quad{mole}\quad{numbers}\quad{in}\quad{catalyst}} \times 100}$

The dispersion of ruthenium shows, among ruthenium in the catalyst, theratio of ruthenium species showing activity on the hydrogenation of CO,and means that, in the same provided amount of ruthenium, higherdispersion of ruthenium indicates larger number of ruthenium species inthe catalyst contributing to the reaction and indicates higher activityon the hydrogenation of CO. Also, both of the CO hydrogenation activityand chain propagation activity (α) are necessary for a catalyst to beused in the FT reaction. Therefore, even if the CO hydrogenationactivity is increased, the catalyst is not suitable for the productionof liquid hydrocarbons as the object of the present invention when thechain propagation activity (α) becomes low. Accordingly, it ispreferable that the catalyst used in the present invention shows from 16to 50% of dispersion of ruthenium after the reduction treatment.

Then, according to the method of the present invention for theproduction of hydrocarbons, the catalyst reduction-treated in the abovemanner is subjected to the FT reaction, namely a synthesis reaction ofhydrocarbons. In the FT reaction of the present invention, the catalystis made into a dispersed state by dispersing it in liquid hydrocarbons,and a synthesis gas is brought into contact with the dispersed catalyst.In this case, as the hydrocarbons in which the catalyst is to bedispersed, similar hydrocarbons used in the reduction treatment which iscarried out in advance can be used. That is, various hydrocarbonsincluding olefins, alkanes, alicyclic hydrocarbons and aromatichydrocarbons and hetero atom-containing hydrocarbons such asoxygen-containing, nitrogen-containing hydrocarbons and the like can beused, so long as they are liquids under the treating conditions. Thenumber of carbons of these hydrocarbons is not particularly limited, butgenerally, those of C₆ to C₄₀ are preferable, those of C₉ to C₄₀ aremore preferable, and those of C₉ to C₃₅ are most preferable. Inhydrocarbons lighter than C₆, a vapor pressure of the solvent becomeshigh so that the range of their reaction condition is limited. Also, inhydrocarbons heavier than C₄₀, solubility of the synthesis gas as thematerial is reduced which causes a possibility that the reactionactivity is reduced. When a method which is carried out by dispersingthe catalyst in liquid hydrocarbons is employed in the reductiontreatment to be carried out in advance, the liquid hydrocarbons used inthe reduction treatment can be used directly in the FT reaction. Anamount of the catalyst to be dispersed in hydrocarbons is aconcentration of from 1 to 50 w/v %, preferably from 3 to 40 w/v %, andmore preferably from 5 to 35 w/v %. When the amount of catalyst is lessthan 1% by mass, the activity is reduced. Although there is a method toreduce quantity of gas flow of the synthesis gas as a method forpreventing decrease in the activity, this is not desirable because thegas (synthesis gas)-liquid (solvent)-solid (catalyst) dispersion isinhibited when the quantity of gas flow of the synthesis gas is reduced.On the other hand, a large amount of the catalyst exceeding 50% by massis not preferable because viscosity of the slurry prepared by dispersingthe catalyst in hydrocarbons becomes so high that dispersion of bubblesbecomes poor and sufficient reaction activity cannot be obtained.

The synthesis gas used in the FT reaction contains hydrogen and carbonmonoxide as main components and may contain other components which donot inhibit the FT reaction. Since the rate (k) of the FT reactiondepends on the hydrogen partial pressure about primarily, it ispreferable that the partial pressure ratio of hydrogen and carbonmonoxide (H₂/CO molar ratio) is 0.6 or more. Since the reactionaccompanies reduction of volume, a higher total value of the partialpressures of hydrogen and carbon monoxide is preferable. Although theupper limit of the partial pressure ratio of hydrogen and carbonmonoxide is not particularly limited, a practical range of this partialpressure rate is suitably from 0.6 to 2.7, preferably from 0.8 to 2.5,and more preferably from 1 to 2.3. When the partial pressure ratio isless than 0.6, the yield of the formed hydrocarbons is reduced, and whenthe partial pressure ratio exceeds 2.7, it causes a tendency to increaselight fractions in the formed hydrocarbons.

Accordingly, in the conditions that carbon dioxide is substantiallyabsent, a total pressure (total value of partial pressures of allcomponents) of the synthesis gas (gas mixture) to be subjected to the FTreaction is preferably from 1 to 10 MPa, more preferably from 1.5 to 6MPa, and most preferably from 1.8 to 4.5 MPa. A value of less than 1 MPais not preferable because the speed of the FT reaction becomesinsufficient to cause a tendency of reducing the yield of gasolinefractions, kerosine and gas oil fractions, wax fractions and the like.On the equilibrium basis, higher partial pressures of hydrogen andcarbon monoxide are advantageous, but the upper limit of these partialpressures is limited from the industrial point of view, because higherpartial pressures increase plant construction cost and the like and theoperation cost increases due to large-scaling of compressors and thelike which are necessary for compression. Herein, the conditions thatcarbon dioxide is substantially absent mean that carbon dioxide isabsent or the amount of the carbon dioxide present is less than 0.5%based on the total pressure of hydrogen and carbon monoxide of thesynthesis gas.

On the other hand, in the conditions that carbon dioxide coexists, asthe carbon dioxide to be coexisted, those which are obtained, forexample, from reforming reaction of a petroleum product, natural gas andthe like can be used without problems, and it may be contaminated withother components which do not inhibit the FT reaction, e.g., it maycontain water vapor, partially oxidized nitrogen and the like as thosewhich are obtained from the steam reforming reaction of petroleumproducts and the like. Also, the carbon dioxide can be positively addedto a synthesis gas which does not contain carbon dioxide, or the carbondioxide in a carbon dioxide-containing synthesis gas obtained byreforming natural gas by a method such as autothermal reforming, steamreforming or the like can be used, namely, a synthesis gas containingcarbon dioxide can be subjected directly to the FT reaction withoutcarrying out a decarbondioxide treatment. When a synthesis gascontaining carbon dioxide is subjected directly to the FT reaction,facility construction cost and operation cost necessary for thedecarbondioxide treatment can be cut down, and production cost ofhydrocarbons obtained by the FT reaction can be reduced. An amount ofthe carbon dioxide to be coexisted is from 0.5 to 50%, preferably from0.5 to 30%, and more preferably from 1 to 10%, based on the totalpressure of hydrogen and carbon monoxide of the synthesis gas to besubjected to the FT reaction. When a partial pressure of carbon dioxidein the synthesis gas (gas mixture) to be subjected to the FT reaction isa low value of less than the above range, the FT reaction-acceleratingeffect of carbon dioxide cannot be obtained, and when it is a high valueof exceeding the above range, partial pressures of hydrogen and carbonmonoxide in the synthesis gas (gas mixture) to be subjected to the FTreaction are reduced and the yield of hydrocarbons is reduced which iseconomically disadvantageous. Regarding the timing to coexist carbondioxide, it may coexist in the reaction system at the early stage of theFT reaction, but in order to improve conversion ratio of carbon monoxideby exerting the FT reaction accelerating effect of carbon dioxide moreeffectively, it is preferable to effect its coexistence by introducingit into the reaction system during a period of from 10 to 100 hoursafter commencement of the FT reaction.

Accordingly, a total pressure (total value of partial pressures of allcomponents) of the synthesis gas (gas mixture) to be subjected to the FTreaction is preferably from 1 to 10 MPa, more preferably from 1.5 to 6MPa, and most preferably from 1.8 to 4.5 MPa. A value of less than 1 MPais not preferable because the chain propagation becomes insufficient tocause a tendency of reducing the yield of gasoline fractions, kerosineand gas oil fractions, wax fractions and the like. On the equilibriumbasis, higher partial pressures of hydrogen and carbon monoxide areadvantageous, but the upper limit of these partial pressures is limitedfrom the industrial point of view, because higher partial pressuresincrease plant construction cost and the like and the operation costincreases due to large-scaling of compressors and the like which arenecessary for compression.

In both conditions that carbon dioxide is substantially absent and thatcarbon dioxide coexists, the gas mixture comprising hydrogen and carbonmonoxide may contain certain amounts of other components, such asexample, vapor, nitrogen, inert gas and the like, so long as they do notinhibit the FT reaction.

In the FT reaction, when the H₂/CO molar ratio of the synthesis gas isconstant, lower temperature generally accelerates chain propagation andincreases olefin selectivity but reduces CO conversion ratio. On theother hand, higher temperature reduces chain propagation and olefinselectivity but increases CO conversion ratio. Also, when the H₂/COratio becomes high, the CO conversion ratio becomes high and the chainpropagation and olefin selectivity are reduced, and the opposite occurswhen the H₂/CO ratio becomes low. In the present invention, although thedegree of the effects of these factors on the reaction varies dependingon the kind of catalyst to be used and the like, the reactiontemperature under the conditions that carbon dioxide is substantiallyabsent is preferably from 170 to 300° C., more preferably of from 190 to290° C., and most preferably from 200 to 290° C., and the reactiontemperature under the conditions that carbon dioxide coexists ispreferably from 200 to 350° C., more preferably from 210 to 310° C., andmost preferably from 220 to 290° C.

When hydrocarbons are synthesized in the coexistence of carbon dioxidefrom a gas mixture containing hydrogen and carbon monoxide as the maincomponents according to the method of the present invention for theproduction of hydrocarbons, good results are obtained in that the COconversion ratio becomes 60% or more by one path (once throughconversion), the chain propagation probability (α) becomes from 0.86 to0.95, the olefin/paraffin ratio in a lower hydrocarbon, e.g., in a C₃hydrocarbon, becomes from 3 to 5, and the C₅+ productivity becomes from400 to 1,100 g/kg/hr. Also, by subjecting a synthesis gas containingcarbon dioxide directly to the FT reaction, facility construction costand operation cost necessary for the decarbondioxide treatment can becut down, and a synthesis gas containing a large amount of carbondioxide, derived from a poor quality natural gas containing a largeamount of carbon dioxide, can be used as the starting material.

Also, the CO conversion ratio, chain propagation probability (α) and C₅+productivity are defined by the following equations.CO Conversion Ratio:${{CO}\quad{conversion}\quad{ratio}} = {\frac{A - B}{A} \times 100}$

A: CO mole numbers in synthetic gas per unit hour

B: CO mole numbers in outlet gas per unit hour

Chain Propagation Probability (α):

When the mass ratio in a product of a hydrocarbon of carbon numbers n isdefined as Mn and the chain propagation probability (α) is defined as α,the following relationship is formed according to the Schultz-Florydistribution. Thus, the a value can be known from the slope log α whenlog (Mn/n) and n are plotted.log(Mn/n)=log((1−α)²/α)+n·log αProductivity of C₅+:

Productivity of C₅+ means the produced amount of C₅+ per catalyst weightper unit hour and is defined by the following equation:C₅+ productivity=C₅+ production (g)/catalyst weight (kg)/(hr)

The present invention are further illustratively shown below based onExamples and Comparative Examples, but the present invention is notlimited to these examples.

Also, CO and CH₄ in the following examples was analyzed by thermalconductivity gas chromatography (TCD-GC) using active carbon (60/80mesh) as the separation column. Furthermore, a synthesis gas was used byadding 10 vol % of Ar as the internal standard. Moreover, peak positionsand peak areas of CO and CH₄ were analyzed qualitatively andquantitatively by comparing them with Ar. In the analysis of C₁ to C₆hydrocarbons, detection and determination of the hydrocarbons werecarried out by flame ionization detector gas chromatography (FID-GC)using a capillary column (Al₂O₃/KCl PLOT) as the separation column andby comparing with C₁ (methane) which can be analyzed in common withTCD-GC. In addition, in the analysis of C₅ to C₄₀ hydrocarbons,detection and determination of these hydrocarbons were carried out byFID-GC equipped with a capillary column (TC-1) and by comparing with C₅and C₆ which can be analyzed in common with light hydrocarbons (C₁ toC₆). The specific surface area of the catalyst (including carrier) wasmeasured by the BET method using an automatic surface area measuringapparatus (Belsorp 28, manufactured by Bell Japan Corp.) and usingnitrogen as the probe molecule. Chemical components of the catalyst wasidentified by ICP (CQM-10000P, manufactured by Shimadzu Corporation),the particle distribution was obtained using a particle size measuringapparatus (Mastersizer MSX-46, manufactured by Malvern) by a laser beamscattering method, and the structure of manganese oxide was analyzed byX-ray diffraction (RINT 2500, manufactured by Rigaku IndustrialCorporation).

For the measurement of the mole numbers of CO adsorbed on the catalyst,a full-automatic catalyst-gas adsorption measuring apparatus (R-6015,manufactured by Ohkurariken Co., Ltd.) integrated with TCD gaschromatography was used. Regarding the adsorbed CO mole number measuringprocedure, helium gas was used as the carrier gas, and hydrogen gas asthe reducing gas, and a catalyst put into a test tube was firstly heatedto reducing temperature by flowing hydrogen gas to carry out reductionand then cooled to 50° C. by changing to helium gas, and thereafter, COgas was fed into the test tube at a predetermined flow rate to measurethe mole number of adsorbed CO.

EXAMPLE 1

Purified water (hereinafter referred to as “water”) was added dropwiseto alkaline alumina powder which had been thoroughly dried in advance,and saturated amount of water absorption was calculated. The saturatedamount of water absorption was 0.9 ml/g in this case. Aluminum oxide (30g) was impregnated with an aqueous solution prepared by dissolving 168 gof manganese nitrate hexahydrate in 27 ml of water, allowed to stand forabout 4 hours, dried at a temperature of 110° C. in the air, and thenburned at 600° C. for 3 hours in the air in a muffle furnace. The thusobtained carrier comprising aluminum oxide and manganese oxide wasimpregnated with an aqueous solution prepared by dissolving 0.2 g ofsodium carbonate (Na assay: 43.2% by mass) in 27 g of water, followed bydrying at a temperature of 110° C. in the air and then burned at 600° C.for 3 hours in a muffle furnace. Thereafter, the thus obtained carrierby impregnating the carrier comprising aluminum oxide and manganeseoxide with sodium was further impregnated with an aqueous solutionprepared by dissolving 2.2 g of ruthenium chloride (Ru assay: 36% bymass) in 27 g of water, allowed to stand for 1 hour and then dried at atemperature of 50° C. in the air. The dried product was transferred intoan agate mortar, pulverized and then screened into a catalyst particledistribution of from 5 to 200 μm to obtain Catalyst A. Catalyst A has anaverage particle size of 95 μm, a bulk density of 1.6 g/ml and aspecific surface area of 100 m²/g. As a result of the structuralanalysis by X-ray diffraction, the manganese oxide was Mn₂O₃ having anaverage number of charges of Mn³⁺. Also, as a result of compositionalanalysis using ICP, it contained 1% by mass in terms of Ru, 0.1% by massin terms of Na, 60% by mass of Mn₂O₃ and the balance as aluminum oxide(aluminum oxide:manganese oxide=100 parts by mass: 154 parts by mass).Catalyst A (0.3 g) and 30 ml of a dispersion medium normal hexadecane(n-C₁₆H₃₄, hereinafter referred to as “solvent”) (slurry concentration:1 g/100 ml) were packed in a 100 ml capacity reaction vessel, andhydrogen was brought into contact with Catalyst A under a hydrogenpartial pressure of 10 MPa·G, at a temperature of 140° C. and at a flowrate of 100 ml/min (STP: standard temperature and pressure) to carry outthe reduction for 1 hour. After the reduction, the atmosphere wasreplaced by helium gas, the temperature was adjusted to 100° C., and thepressure was adjusted to ordinary pressure. Thereafter, the atmospherewas changed to a gas mixture comprising 10 vol % of argon, 56.3 vol % ofcarbon monoxide and hydrogen as the balance (H₂/CO ratio: 0.6,hereinafter referred to as “synthesis gas”), the FT reaction was carriedout at a temperature of 210° C. under a total pressure of hydrogen andcarbon monoxide partial pressures (hereinafter referred to as “H₂+COpressure”) of 10 MPa·G. The feeding amount of the synthesis gas wasadjusted to 60% as one path CO conversion ratio (hereinafter referred toas “conversion ratio”), and the W/F (weight/flow (g·hr/mol)) was 11.5g·hr/mol. As a result of carrying out the FT reaction, the chainpropagation probability (α) was 0.92, the C₅+ selectivity was 92%, theolefin/paraffin ratio in C₃ was 4, and the C₅+ productivity was 420g/kg/hr.

EXAMPLE 2

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 113 g of manganese nitrate, then with 0.3 g of sodiumcarbonate and then with 2.7 g of ruthenium chloride to thereby obtainCatalyst B having physical properties of a particle distribution of from5 to 200 μm, an average particle size of 95 μm, a bulk density of 1.45g/ml and a specific surface area of 140 m²/g and comprising 1.5% by massin terms of Ru, 0.2% by mass in terms of Na, 50% by mass of Mn₂O₃ andthe balance as aluminum oxide (aluminum oxide:manganese oxide=100 partsby mass: 104 parts by mass). Catalyst B (0.9 g) and 30 ml of the solvent(slurry concentration: 3 g/100 ml) were packed in a reaction vessel, andhydrogen was brought into contact with Catalyst B under a hydrogenpartial pressure of 6 MPa·G, at a temperature of 150° C. and at a flowrate of 100 ml/min (STP) to carry out the reduction for 0.5 hour. Afterthe reduction, the atmosphere was replaced by helium gas, thetemperature was adjusted to 100° C., and the pressure was adjusted toordinary pressure. Thereafter, the atmosphere was changed to a synthesisgas comprising 10 vol % of argon, 50 vol % of carbon monoxide andhydrogen as the balance (H₂/CO ratio: 0.8), the FT reaction was carriedout at a temperature of 230° C. under an H₂+CO pressure of 6 MPa·G. Thefeeding amount of the synthesis gas yielding a conversion ratio of 60%was W/F 11.1 g·hr/mol. As a result of carrying out the reaction, thechain propagation probability (α) was 0.92, the C₅+ selectivity was 90%,the olefin/paraffin ratio in C₃ was 4, and the C₅+ productivity was 380g/kg/hr.

EXAMPLE 3

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 6.6 g of manganese nitrate, then with 2.6 g of sodiumcarbonate and then with 10.5 g of ruthenium chloride to thereby obtainCatalyst C having physical properties of a particle distribution of from10 to 180 μm, an average particle size of 90 μm, a bulk density of 0.8g/ml and a specific surface area of 300 m²/g and comprising 10% by massin terms of Ru, 3% by mass in terms of Na, 5% by mass of Mn₂O₃ and thebalance as aluminum oxide (aluminum oxide:manganese oxide=100 parts bymass: 6 parts by mass). Catalyst C (10.5 g) was were packed in areaction vessel, and hydrogen was brought into contact with Catalyst Cunder a hydrogen partial pressure of 1 MPa·G, at a temperature of 220°C. and at a flow rate of 100 ml/min (STP) to carry out 48 hour ofreduction. After the reduction, the atmosphere was replaced by heliumgas, the temperature was adjusted to 100° C., the pressure was adjustedto ordinary pressure, and 30 ml of the solvent (slurry concentration: 35g/100 ml) was fed into the reaction vessel under a forced pressure.Thereafter, the atmosphere was changed to a synthesis gas comprising 10vol % of argon, 27.3 vol % of carbon monoxide and hydrogen as thebalance (H₂/CO ratio: 2.3), the FT reaction was carried out at atemperature of 280° C. under an H₂ + CO pressure of 1.8 MPa·G. Thefeeding amount of the synthesis gas yielding a conversion ratio of 60%was W/F 2.2 g·hr/mol. As a result of carrying out the FT reaction, thechain propagation probability (α) was 0.89, the C₅+ selectivity was 82%,the olefin/paraffin ratio in C₃ was 3.8, and the C₅+ productivity was930 g/kg/hr.

EXAMPLE 4

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 17.3 g of manganese nitrate, then with 7.8 g of sodiumcarbonate and then with 27.2 g of ruthenium chloride to thereby obtainCatalyst D having physical properties of a particle distribution of from5 to 40 μm, an average particle size of 20 μm, a bulk density of 0.9g/ml and a specific surface area of 220 m²/g and comprising 20% by massin terms of Ru, 7% by mass in terms of K, 10% by mass of Mn₂O₃ and thebalance as aluminum oxide (aluminum oxide:manganese oxide=100 parts bymass: 16 parts by mass). Catalyst D (12 g) was packed in a reactionvessel, and hydrogen was brought into contact with Catalyst D under ahydrogen partial pressure of 0.5 MPa·G, at a temperature of 250° C. andat a flow rate of 100 ml/min (STP) to carry out the reduction for 24hours. After the reduction, the atmosphere was replaced by helium gas,the temperature was adjusted to 100° C., the pressure was adjusted toordinary pressure, and 30 ml of the solvent (slurry concentration: 40g/100 ml) was fed into the reaction vessel under a forced pressure.Thereafter, the atmosphere was changed to a synthesis gas comprising 10vol % of argon, 25.7 vol % of carbon monoxide and hydrogen as thebalance (H₂/CO ratio: 0.8), the FT reaction was carried out at atemperature of 290° C. under an H₂+CO pressure of 1.5 MPa·G. The feedingamount of the synthesis gas yielding a conversion ratio of 60% was W/F2.0 g·hr/mol. As a result of carrying out the FT reaction, the chainpropagation probability (α) was 0.88, the C₅+ selectivity was 83%, theolefin/paraffin ratio in C₃ was 3.9, and the C₅+ productivity was 1000g/kg/hr.

EXAMPLE 5

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 85.7 g of manganese nitrate, then with 23.4 g of sodiumcarbonate and then with 85.7 g of ruthenium chloride to thereby obtainCatalyst E having physical properties of a particle distribution of from5 to 70 μm, an average particle size of 25 μm, a bulk density of 1.8g/ml and a specific surface area of 60 m²/g and comprising 30% by massin terms of Ru, 10% by mass in terms of Na, 30% by mass of Mn₂O₃ and thebalance as aluminum oxide (aluminum oxide:manganese oxide=100 parts bymass: 100 parts by mass). Catalyst E (15 g) was packed in a reactionvessel, and hydrogen was brought into contact with Catalyst E under ahydrogen partial pressure of 0.1 MPa·G, at a temperature of 310° C. andat a flow rate of 100 ml/min (STP) to carry out the reduction for 6minutes. After the reduction, the atmosphere was replaced by helium gas,the temperature was adjusted to 100° C., the pressure was adjusted toordinary pressure, and 30 ml of the solvent (slurry concentration: 3g/100 ml) was fed into the reaction vessel under a forced pressure.Thereafter, the atmosphere was changed to a synthesis gas comprising 10vol % of argon, 50 vol % of carbon monoxide and hydrogen as the balance(H₂/CO ratio: 2.7), the FT reaction was carried out at a temperature of300° C. under an H₂+CO pressure of 1 MPa·G. The feeding amount of thesynthesis gas yielding a conversion ratio of 60% was W/F 2.2 g·hr/mol.As a result of carrying out the FT reaction, the chain propagationprobability (α) was 0.88, the C₅+ selectivity was 80%, theolefin/paraffin ratio in C₃ was 3.9, and the C₅+ productivity was 830g/kg/hr.

EXAMPLE 6

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 168 g of manganese nitrate, then with 0.8 g of calciumnitrate tetrahydrate (Ca assay: 17% by mass) and then with 2.2 g ofruthenium chloride to thereby obtain Catalyst F having physicalproperties of a particle distribution of from 5 to 200 μm, an averageparticle size of 95 μm, a bulk density of 1.6 g/ml and a specificsurface area of 100 m²/g and comprising 1% by mass in terms of Ru, 0.1%by mass in terms of Ca, 60% by mass of Mn₂O₃ and the balance as aluminumoxide (aluminum oxide:manganese oxide=100 parts by mass: 154 parts bymass). Catalyst F (0.3 g) and 30 ml of the solvent (slurryconcentration: 3 g/100 ml) were packed in a reaction vessel, andhydrogen was brought into contact with Catalyst F under a hydrogenpartial pressure of 10 MPa·G, at a temperature of 140° C. and at a flowrate of 100 ml/min (STP) to carry out the reduction for 1 hour. Afterthe reduction, the atmosphere was replaced by helium gas, thetemperature was adjusted to 100° C., and the pressure was adjusted toordinary pressure. The Ru dispersion of Catalyst F after the reductionwas 38%. Thereafter, the atmosphere was changed to a synthesis gascomprising 10 vol % of argon, 56.3 vol % of carbon monoxide and hydrogenas the balance (H₂/CO ratio: 0.6), the FT reaction was started at atemperature of 210° C. under an H₂+CO pressure of 10 MPa·G, and 20 hoursthereafter, the FT reaction was carried out by introducing carbondioxide under a partial pressure of 0.05 MPa. The feeding amount of thesynthesis gas yielding a conversion ratio of 60% was W/F 10.7 g·hr/mol.After 48 hours from the commencement of the reaction, the chainpropagation probability (α) was 0.91, the C₅+ selectivity was 89%, theolefin/paraffin ratio in C₃ was 4, and the C₅+ productivity was 435g/kg/hr. Also, the FT reaction was carried out by repeating the sameprocedure except that introduction of carbon dioxide was not carriedout. As a result, the chain propagation probability (α) was 0.92, theC₅+ selectivity was 92%, the olefin/paraffin ratio in C₃ was 4, and theC₅+ productivity was 420 g/kg/hr.

EXAMPLE 7

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 113 g of manganese nitrate, then with 0.4 g ofpotassium carbonate (K assay: 28.3% by mass) and then with 2.7 g ofruthenium chloride to thereby obtain Catalyst G having physicalproperties of a particle distribution of from 5 to 200 μm, an averageparticle size of 95 μm, a bulk density of 1.45 g/ml and a specificsurface area of 140 m²/g and comprising 1.5% by mass in terms of Ru,0.2% by mass in terms of K, 50% by mass of Mn₂O₃ and the balance asaluminum oxide (aluminum oxide:manganese oxide=100 parts by mass: 104parts by mass.). Catalyst G (0.9 g) and 30 ml of the solvent (slurryconcentration: 3 g/100 ml) were packed in a reaction vessel, andhydrogen was brought into contact with Catalyst G under a hydrogenpartial pressure of 6 MPa·G, at a temperature of 150° C. and at a flowrate of 100 ml/min (STP) to carry out the reduction for 0.5 hour. Afterthe reduction, the atmosphere was replaced by helium gas, thetemperature was adjusted to 100° C., and the pressure was adjusted toordinary pressure. The Ru dispersion of Catalyst G after the reductionwas 39%. Thereafter, the atmosphere was changed to a synthesis gascomprising 10 vol % of argon, 50 vol % of carbon monoxide and hydrogenas the balance (H₂/CO ratio: 0.8), the FT reaction was started at atemperature of 230° C. under an H₂+CO pressure of 6 MPa·G, and 20 hoursthereafter, the FT reaction was carried out by introducing carbondioxide under a partial pressure of 0.06 MPa. The feeding amount of thesynthesis gas yielding a conversion ratio of 60% was W/F 10.1 g·hr/mol.After 48 hours from the commencement of the reaction, the chainpropagation probability (α) was 0.91, the C₅+ selectivity was 88%, theolefin/paraffin ratio in C₃ was 4, and the C₅+ productivity was 405g/kg/hr. Also, the FT reaction was carried out by repeating the sameprocedure except that introduction of carbon dioxide was not carriedout. As a result, the chain propagation probability (α) was 0.92, theC₅+ selectivity was 90%, the olefin/paraffin ratio in C₃ was 4, and theC₅+ productivity was 380 g/kg/hr.

EXAMPLE 8

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 114.8 g of manganese nitrate, then with 0.7 g of sodiumcarbonate (Na assay: 43.2% by mass) and then with 3.6 g of rutheniumchloride to thereby obtain Catalyst H having physical properties of aparticle distribution of from 10 to 180 μm, an average particle size of80 μm, a bulk density of 1.45 g/ml and a specific surface area of 140m²/g and comprising 2% by mass in terms of Ru, 0.5% by mass in terms ofNa, 50% by mass of Mn₂O₃ and the balance as aluminum oxide (aluminumoxide:manganese oxide=100 parts by mass: 105 parts by mass). Catalyst H(1.5 g) was packed in a reaction vessel, and hydrogen was brought intocontact with Catalyst H under a hydrogen partial pressure of 5 MPa·G, ata temperature of 160° C. and at a flow rate of 100 ml/min (STP) to carryout the reduction for 72 hours. After the reduction, the atmosphere wasreplaced by helium gas, the temperature was adjusted to 100° C., thepressure was adjusted to ordinary pressure, and then 30 ml of thesolvent (slurry concentration: 5 g/100 ml) was fed into the reactionvessel under a forced pressure. The Ru dispersion of Catalyst H afterthe reduction was 33%. Thereafter, the atmosphere was changed to asynthesis gas comprising 10 vol % of argon, 45 vol % of carbon monoxideand hydrogen as the balance (H₂/CO ratio: 1), the FT reaction wasstarted at a temperature of 240° C. under an H₂+CO pressure of 4.5MPa·G, and 20 hours thereafter, the FT reaction was carried out byintroducing carbon dioxide under a partial pressure of 0.45 MPa. Thefeeding amount of the synthesis gas yielding a conversion ratio of 60%was W/F 7.5 g·hr/mol. After 48 hours from the commencement of thereaction, the chain propagation probability (α) was 0.90, the C₅+selectivity was 86%, the olefin/paraffin ratio in C₃ was 3.9, and theC₅+ productivity was 485 g/kg/hr. Also, the FT reaction was carried outby repeating the same procedure except that introduction of carbondioxide was not carried out. As a result, the chain propagationprobability (α) was 0.91, the C₅+ selectivity was 88%, theolefin/paraffin ratio in C₃ was 4, and the C₅+ productivity was 420g/kg/hr.

EXAMPLE 9

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 49.5 g of manganese nitrate, then with 1 g of sodiumcarbonate and then with 3.9 g of ruthenium chloride to thereby obtainCatalyst I having physical properties of a particle distribution of from20 to 150 μm, an average particle size of 60 μm, a bulk density of 1.25g/ml and a specific surface area of 165 m²/g and comprising 3% by massin terms of Ru, 0.9% by mass in terms of Na, 30% by mass of Mn₂O₃ andthe balance as aluminum oxide (aluminum oxide:manganese oxide=100 partsby mass: 45 parts by mass). Catalyst I (9 g) and 30 ml of the solvent(slurry concentration: 30 g/100 ml) were packed in a reaction vessel,and hydrogen was brought into contact with Catalyst I under a hydrogenpartial pressure of 2 MPa·G, at a temperature of 170° C. and at a flowrate of 100 ml/min (STP) to carry out the reduction for 4 hours. Afterthe reduction, the atmosphere was replaced by helium gas, thetemperature was lowered to 100° C., and the pressure was returned toordinary pressure. The Ru dispersion of Catalyst I after the reductionwas 33%. Thereafter, the atmosphere was changed to a synthesis gascomprising 10 vol % of argon, 30 vol % of carbon monoxide and hydrogenas the balance (H₂/CO ratio: 2), the FT reaction was started at atemperature of 270° C. under an H₂+CO pressure of 2 MPa·G, and 20 hoursthereafter, the FT reaction was carried out by introducing carbondioxide under a partial pressure of 0.2 MPa. The feeding amount of thesynthesis gas yielding a conversion ratio of 60% was W/F 4.0 g·hr/mol.After 48 hours from the commencement of the reaction, the chainpropagation probability (α) was 0.89, the C₅+ selectivity was 85%, theolefin/paraffin ratio in C₃ was 3.9, and the C₅+ productivity was 595g/kg/hr. Also, the FT reaction was carried out by repeating the sameprocedure except that introduction of carbon dioxide was not carriedout. As a result, the chain propagation probability (α) was 0.9, the C₅+selectivity was 85%, the olefin/paraffin ratio in C₃ was 4, and the C₅+productivity was 500 g/kg/hr.

EXAMPLE 10

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 50.3 g of manganese nitrate, then with 1 g of sodiumcarbonate and then with 5.3 g of ruthenium chloride to thereby obtainCatalyst J having a particle distribution of from 20 to 125 μm, anaverage particle size of 50 μm, a bulk density of 1.25 g/ml and aspecific surface area of 165 m²/g and comprising 4% by mass in terms ofRu, 0.9% by mass in terms of Na, 30% by mass of Mn₂O₃ and the balance asaluminum oxide (aluminum oxide:manganese oxide=100 parts by mass: 46parts by mass). Catalyst J (9 g) and 30 ml of the solvent (slurryconcentration: 30 g/100 ml) were packed in a reaction vessel, andhydrogen was brought into contact with Catalyst J under a hydrogenpartial pressure of 2 MPa·G, at a temperature of 170° C. and at a flowrate of 100 ml/min (STP) to carry out the reduction for 4 hours. Afterthe reduction, the atmosphere was replaced by helium gas, and thetemperature was lowered to 100° C., and the pressure was adjusted toordinary pressure. The Ru dispersion of Catalyst J after the reductionwas 30%. Thereafter, the atmosphere was changed to a synthesis gascomprising 10 vol % of argon, 30 vol % of carbon monoxide and hydrogenas the balance (H₂/CO ratio: 2), the FT reaction was started at atemperature of 270° C. under an H₂+CO pressure of 2 MPa·G, and 20 hoursthereafter, the FT reaction was carried out by introducing carbondioxide under a partial pressure of 0.2 MPa. The feeding amount of thesynthesis gas yielding a conversion ratio of 60% was W/F 2.3 g·hr/mol.After 48 hours from the commencement of the reaction, the chainpropagation probability (α) was 0.89, the C₅+ selectivity was 85%, theolefin/paraffin ratio in C₃ was 3.9, and the C₅+ productivity was 1050g/kg/hr. Also, the FT reaction was carried out by repeating the sameprocedure except that introduction of carbon dioxide was not carriedout. As a result, the chain propagation probability (α) was 0.9, the C₅+selectivity was 85%, the olefin/paraffin ratio in C₃ was 4, and the C₅+productivity was 900 g/kg/hr.

EXAMPLE 11

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 6.6 g of manganese nitrate, then with 3.2 g ofpotassium carbonate and then with 10.5 g of ruthenium chloride tothereby obtain Catalyst K having a particle distribution of from 10 to180 μm, an average particle size of 90 μm, a bulk density of 0.8 g/mland a specific surface area of 300 m²/g and comprising 10% by mass interms of Ru, 3% by mass in terms of K, 5% by mass of Mn₂O₃ and thebalance as aluminum oxide (aluminum oxide:manganese oxide=100 parts bymass: 6 parts by mass). Catalyst K (10.5 g) was packed in a reactionvessel, and hydrogen was brought into contact with Catalyst K under ahydrogen partial pressure of 1 MPa·G, at a temperature of 220° C. and ata flow rate of 100 ml/min (STP) to carry out the reduction for 48 hours.After the reduction, the atmosphere was replaced by helium gas, thetemperature was adjusted to 100° C., the pressure was adjusted toordinary pressure, and then 30 ml of the solvent (slurry concentration:35 g/100 ml) was fed into the reaction vessel under a forced pressure.The Ru dispersion of Catalyst K after the reduction was 29%. Thereafter,the atmosphere was changed to a synthesis gas comprising 10 vol % ofargon, 27.3 vol % of carbon monoxide and hydrogen as the balance (H₂/COratio: 2.3), the FT reaction was started at a temperature of 280° C.under an H₂+CO pressure of 1.8 MPa·G, and 20 hours thereafter, the FTreaction was carried out by introducing carbon dioxide under a partialpressure of 0.9 MPa. The feeding amount of the synthesis gas yielding aconversion ratio of 60% was W/F 2.0 g·hr/mol. After 48 hours from thecommencement of the reaction, the chain propagation probability (α) was0.89, the C₅+ selectivity was 81%, the olefin/paraffin ratio in C₃ was3.7, and the C₅+ productivity was 1030 g/kg/hr. Also, the FT reactionwas carried out by repeating the same procedure except that introductionof carbon dioxide was not carried out. As a result, the chainpropagation probability (α) was 0.89, the C₅+ selectivity was 82%, theolefin/paraffin ratio in C₃ was 3.8, and the C₅+ productivity was 930g/kg/hr.

EXAMPLE 12

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 17.3 g of manganese nitrate, then with 34.2 g ofcalcium nitrate and then with 27.2 g of ruthenium chloride to therebyobtain Catalyst L having a particle distribution of from 5 to 40 μm, anaverage particle size of 20 μm, a bulk density of 0.9 g/ml and aspecific surface area of 220 m²/g and comprising 20% by mass in terms ofRu, 7% by mass in terms of Ca, 10% by mass of Mn₂O₃ and the balance asaluminum oxide (aluminum oxide:manganese oxide=100 parts by mass: 16parts by mass). Catalyst L (12 g) was packed in a reaction vessel, andhydrogen was brought into contact with. Catalyst L under a hydrogenpartial pressure of 0.5 MPa·G, at a temperature of 250° C. and at a flowrate of 100 ml/min (STP) to carry out the reduction for 24 hours. Afterthe reduction, the atmosphere was replaced by helium gas, thetemperature was adjusted to 100° C., the pressure was adjusted toordinary pressure, and then 30 ml of the solvent (slurry concentration:40 g/100 ml) was fed into the reaction vessel under a forced pressure.The Ru dispersion of Catalyst L after the reduction was 22%. Thereafter,the atmosphere was changed to a synthesis gas comprising 10 vol % ofargon, 25.7 vol % of carbon monoxide and hydrogen as the balance (H₂/COratio: 2.5), the FT reaction was started at a temperature of 300° C.under an H₂+CO pressure of 1.5 MPa·G, and 20 hours thereafter, the FTreaction was carried out by introducing carbon dioxide under a partialpressure of 0.45 MPa. The feeding amount of the synthesis gas yielding aconversion ratio of 60% was W/F 1.8 g·hr/mol. After 48 hours from thecommencement of the reaction, the chain propagation probability (α) was0.88, the C₅+ selectivity was 80%, the olefin/paraffin ratio in C₃ was3.9, and the C₅+ productivity was 1000 g/kg/hr. Also, the FT reactionwas carried out by repeating the same procedure except that introductionof carbon dioxide was not carried out. As a result, the chainpropagation probability (α) was 0.88, the C₅+ selectivity was 80%, theolefin/paraffin ratio in C₃ was 3.9, and the C₅+ productivity was 1000g/kg/hr.

EXAMPLE 13

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 85.7 g of manganese nitrate, then with 102.7 g ofcalcium nitrate and then with 85.7 g of ruthenium chloride to therebyobtain Catalyst M having a particle distribution of from 5 to 70 μm, anaverage particle size of 25 μm, a bulk density of 1.8 g/ml and aspecific surface area of 60 m²/g and comprising 30% by mass in terms ofRu, 10% by mass in terms of Ca, 30% by mass of Mn₂O₃ and the balance asaluminum oxide (aluminum oxide:manganese oxide=100 parts by mass: 100parts by mass). Catalyst M (15 g) was packed in a reaction vessel, andhydrogen was brought into contact with Catalyst M under a hydrogenpartial pressure of 0.1 MPa·G, at a temperature of 310° C. and at a flowrate of 100 ml/min (STP) to carry out the reduction for 6 minutes. Afterthe reduction, the atmosphere was replaced by helium gas, thetemperature was adjusted to 100° C., the pressure was adjusted toordinary pressure, and then 30 ml of the solvent (slurry concentration:50 g/100 ml) was fed into the reaction vessel under a forced pressure.The Ru dispersion of Catalyst M after the reduction was 18%. Thereafter,the atmosphere was changed to a synthesis gas comprising 10 vol % ofargon, 24.3 vol % of carbon monoxide and hydrogen as the balance (H₂/COratio: 2.7), the FT reaction was started at a temperature of 320° C.under an H₂+CO pressure of 1 MPa·G, and 20 hours thereafter, the FTreaction was carried out by introducing carbon dioxide under a partialpressure of 0.3 MPa. The feeding amount of the synthesis gas yielding aconversion ratio of 60% was W/F 2.0 g·hr/mol. After 48 hours from thecommencement of the reaction, the chain propagation probability (α) was0.86, the C₅+ selectivity was 78%, the olefin/paraffin ratio in C₃ was3.6, and the C₅+ productivity was 930 g/kg/hr. Also, the FT reaction wascarried out by repeating the same procedure except that introduction ofcarbon dioxide was not carried out. As a result, the chain propagationprobability (α) was 0.88, the C₅+ selectivity was 80%, theolefin/paraffin ratio in C₃ was 3.8, and the C₅+ productivity was 830g/kg/hr.

COMPARATIVE EXAMPLE 1

A catalyst was prepared in the same manner as in Example 1 except thatthe burning temperature was set to 800° C. to thereby obtain Catalyst Nhaving a particle distribution of from 10 to 150 μm, an average particlesize of 80 μm, a bulk density of 1.8 g/ml and a specific surface area of55 m²/g and comprising 3% by mass in terms of Ru, 0.9% by mass in termsof Na, 30% by mass of Mn₂O₃ and the balance as aluminum oxide (aluminumoxide:manganese oxide=100 parts by mass: 45 parts by mass). Catalyst N(9 g) and 30 ml of the solvent (slurry concentration: 30 g/100 ml) werepacked in a reaction vessel, and hydrogen was brought into contact withCatalyst N under a hydrogen partial pressure of 2 MPa·G, at atemperature of 170° C. and at a flow rate of 100 ml/min (STP) to carryout the reduction for 2 hours. After the reduction, the atmosphere wasreplaced by helium gas, the temperature was adjusted to 100° C., thepressure was adjusted to ordinary pressure, and then the atmosphere waschanged to a synthesis gas comprising 10% by volume of argon, 30% byvolume of carbon monoxide and hydrogen as the balance (H₂/CO ratio: 2)to carry out the FT reaction at a temperature of 270° C. under an H₂+COpressure of 2 MPa·G. The feeding amount of the synthesis gas yielding aconversion ratio of 60% was W/F 16.4 g·hr/mol. As a result of carryingout the FT reaction, the chain propagation probability (α) was 0.9, theC₅+ selectivity was 85%, the olefin/paraffin ratio in C₃ was 4, and theC₅+ productivity was 145 g/kg/hr.

Since the specific surface area of the catalyst is too small in thisexample, the C₅+ productivity is low.

COMPARATIVE EXAMPLE 2

A catalyst was prepared in the same manner as in Example 9 except thatthe burning temperature was set to 900° C. to thereby obtain Catalyst Ohaving physical properties of a particle distribution of from 10 to 150μm, an average particle size of 80 μm, a bulk density of 2 g/ml and aspecific surface area of 50 m²/g and comprising 3% by mass in terms ofRu, 0.9% by mass in terms of Na, 30% by mass of Mn₂O₃ and the balance asaluminum oxide (aluminum oxide:manganese oxide=100 parts by mass: 45parts by mass). Catalyst O (9 g) and 30 ml of the solvent (slurryconcentration: 30 g/100 ml) were packed in a reaction vessel, Catalyst Owas subjected to hydrogen reduction in the same manner as in ComparativeExample 1, and then the FT reaction was carried out by bringing asynthesis gas comprising argon, carbon monoxide and hydrogen intocontact with this catalyst in the same manner as in ComparativeExample 1. The feeding amount of the synthesis gas yielding a conversionratio of 60% was W/F 18.3 g·hr/mol. As a result of carrying out the FTreaction, the chain propagation probability (α) was 0.9, the C₅+selectivity was 85%, the olefin/paraffin ratio in C₃ was 4, and the C₅+productivity was 130 g/kg/hr.

Since the bulk density of the catalyst is too large and its specificsurface area is too small in this example, the C₅+ productivity is low.

COMPARATIVE EXAMPLE 3

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 47.5 g of manganese nitrate, then with 0.9 g of sodiumcarbonate and then with 0.1 g of ruthenium chloride to thereby obtainCatalyst P having a particle distribution of from 10 to 150 μm, anaverage particle size of 80 μm, a bulk density of 1.25 g/ml and aspecific surface area of 160 m²/g and comprising 0.1% by mass in termsof Ru, 0.9% by mass in terms of Na, 30% by mass of Mn₂O₃ and the balanceas aluminum oxide (aluminum oxide:manganese oxide=100 parts by mass: 43parts by mass). Catalyst P (9 g) and 30 ml of the solvent (slurryconcentration: 30 g/100 ml) were packed in a reaction vessel, Catalyst Pwas subjected to hydrogen reduction in the same manner as in ComparativeExample 1, and then the FT reaction was carried out by bringing asynthesis gas comprising argon, carbon monoxide and hydrogen intocontact with this catalyst in the same manner as in ComparativeExample 1. The feeding amount of the synthesis gas yielding a conversionratio of 60% was W/F 29.8 g·hr/mol. As a result of carrying out the FTreaction, the chain propagation probability (α) was 0.9, the C₅+selectivity was 85%, the olefin/paraffin ratio in C₃ was 4, and the C₅+productivity was 80 g/kg/hr.

Since the provided amount of ruthenium of the catalyst is too small inthis example, the C₅+ productivity is low.

COMPARATIVE EXAMPLE 4

In the same manner as in Example 1, 10 g of alkaline alumina powder wasimpregnated with 37.5 g of manganese nitrate, then with 0.7 g of sodiumcarbonate and then with 39.3 g of ruthenium chloride to thereby obtainCatalyst Q having a particle distribution of from 10 to 150 μm, anaverage particle size of 80 μm, a bulk density of 1.4 g/ml and aspecific surface area of 160 m²/g and comprising 40% by mass in terms ofRu, 0.9% by mass in terms of Na, 30% by mass of Mn₂O₃ and the balance asaluminum oxide (aluminum oxide:manganese oxide=100 parts by mass: 103parts by mass). Catalyst Q (9 g) and 30 ml of the solvent (slurryconcentration: 30 g/100 ml) were packed in a reaction vessel, thecatalyst was subjected to hydrogen reduction in the same manner as inComparative Example 1, and then the FT reaction was carried out bybringing a synthesis gas comprising argon, carbon monoxide and hydrogeninto contact with this catalyst in the same manner as in ComparativeExample 1. The feeding amount of the synthesis gas yielding a conversionratio of 60% was W/F 7.9 g·hr/mol. As a result of carrying out the FTreaction, the chain propagation probability (α) was 0.9, the C₅+selectivity was 85%, the olefin/paraffin ratio in C₃ was 4, and the C₅+productivity was 300 g/kg/hr.

Since the provided amount of ruthenium of the catalyst is too large inthis example, the C₅+ productivity is low.

COMPARATIVE EXAMPLE 5

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 49.5 g of manganese nitrate, then with 32 g of sodiumcarbonate and then with 3.9 g of ruthenium chloride to thereby obtainCatalyst R having a particle distribution of from 10 to 150 μm, anaverage particle size of 80 μm, a bulk density of 1.25 g/ml and aspecific surface area of 160 m²/g and comprising 3% by mass in terms ofRu, 30% by mass in terms of Na, 30% by mass of Mn₂O₃ and the balance asaluminum oxide (aluminum oxide:manganese oxide=100 parts by mass: 81parts by mass). Catalyst R (9 g) and 30 ml of the solvent (slurryconcentration: 30 g/100 ml) were packed in a reaction vessel, thecatalyst was subjected to hydrogen reduction in the same manner as inComparative Example 1, and then the FT reaction was carried out bybringing a synthesis gas comprising argon, carbon monoxide and hydrogeninto contact with Catalyst R in the same manner as in ComparativeExample 1. The feeding amount of the synthesis gas yielding a conversionratio of 60% was W/F 9.9 g·hr/mol. As a result of carrying out the FTreaction, the chain propagation probability (α) was 0.9, the C₅+selectivity was 85%, the olefin/paraffin ratio in C₃ was 4, and the C₅+productivity was 240 g/kg/hr.

Since the amount of the sodium compound provided on the catalyst is toolarge in this example, the C₅+ productivity is low.

COMPARATIVE EXAMPLE 6

In the same manner as in Example 1, 40 g of alkaline alumina powder wasimpregnated with 0.9 g of sodium carbonate and then with 3.6 g ofruthenium chloride to thereby obtain Catalyst S having a particledistribution of from 10 to 150 μm, an average particle size of 80 μm, abulk density of 0.75 g/ml and a specific surface area of 360 m²/g andcomprising 3% by mass in terms of Ru, 0.9% by mass in terms of Na andthe balance as aluminum oxide (no manganese oxide). Catalyst S (9 g) and30 ml of the solvent (slurry concentration: 30 g/100 ml) were packed ina reaction vessel, and hydrogen was brought into contact with Catalyst Sunder a hydrogen partial pressure of 2 MPa·G, at a temperature of 170°C. and at a flow rate of 100 ml/min (STP) to carry out the reduction for4 hours. After the reduction, the atmosphere was replaced by helium gas,the temperature was adjusted to 100° C., and the pressure was adjustedto ordinary pressure. The Ru dispersion of Catalyst S after thereduction was 65%. Thereafter, the atmosphere was changed to a synthesisgas comprising 10 vol % of argon, 30 vol % of carbon monoxide andhydrogen as the balance (H₂/CO ratio: 2), the FT reaction was started ata temperature of 270° C. under an H₂+CO pressure of 2 MPa·G, and 20hours thereafter, the FT reaction was carried out by introducing carbondioxide under a partial pressure of 0.2 MPa. The feeding amount of thesynthesis gas yielding a conversion ratio of 60% was W/F 12.9 g·hr/mol.After 48 hours from the commencement of the reaction, the chainpropagation probability (α) was 0.75, the C₅+ selectivity was 69%, theolefin/paraffin ratio in C₃ was 0.1, and the C₅+ productivity was 150g/kg/hr. Also, the FT reaction was carried out by repeating the sameprocedure except that introduction of carbon dioxide was not carriedout. As a result, the chain propagation probability (α) was 0.8, the C₅+selectivity was 73%, the olefin/paraffin ratio in C₃ was 0.5, and theC₅+ productivity was 210 g/kg/hr.

Since manganese oxide was not used in the catalyst in this example, eachof the chain propagation probability (α), C₅+ selectivity andolefin/paraffin ratio in C₃ was small and the C₅+ productivity was alsolow, and these values were further reduced when carbon dioxide coexists.

COMPARATIVE EXAMPLE 7

A catalyst was prepared in the same manner as in Example 1, except that145 g of manganese nitrate was burned and impregnated with 0.9 g ofsodium carbonate and then with 0.1 g of ruthenium chloride to therebyobtain Catalyst T having a particle distribution of from 10 to 150 μm,an average particle size of 80 μm, a bulk density of 2.4 g/ml and aspecific surface area of 40 m²/g and comprising 3% by mass in terms ofRu, 0.9% by mass in terms of Na and Mn₂O₃ as the balance (no aluminumoxide). Catalyst T (9 g) and 30 ml of the solvent (slurry concentration:30 g/100 ml) were packed in a reaction vessel, the catalyst wassubjected to hydrogen reduction in the same manner as in ComparativeExample 6, the FT reaction was started by bringing a synthesis gascomprising argon, carbon monoxide and hydrogen into contact with thiscatalyst in the same manner as in Comparative Example 6, and then the FTreaction was carried out by introducing carbon dioxide. The Rudispersion of Catalyst T after the reduction was 14%. Also, the feedingamount of the synthesis gas yielding a conversion ratio of 60% was W/F8.3 g·hr/mol. After 48 hours from the commencement of the reaction, thechain propagation probability (α) was 0.89, the C₅+ selectivity was 83%,the olefin/paraffin ratio in C₃ was 5, and the C₅+ productivity was 280g/kg/hr. Also, the FT reaction was carried out by repeating the sameprocedure except that introduction of carbon dioxide was not carriedout. As a result, the chain propagation probability (α) was 0.9, the C₅+selectivity was 85%, the olefin/paraffin ratio in C₃ was 6, and the C₅+productivity was 150 g/kg/hr.

Since aluminum oxide was not used in the catalyst in this example, thespecific surface area of the catalyst was too small and the bulk densityof the catalyst was too large, so that the C₅+ productivity was low.However, the C₅+ productivity was improved to some extent in thecoexistence of carbon dioxide.

COMPARATIVE EXAMPLE 8

In the same manner as in Example 1, 30 g of alkaline alumina powder wasimpregnated with 49.5 g of manganese nitrate and then with 3.9 g ofruthenium chloride to thereby obtain Catalyst U having a particledistribution of from 10 to 150 μm, an average particle size of 80 μm, abulk density of 1.25 g/ml and a specific surface area of 160 m²/g andcomprising 3% by mass in terms of Ru (no Na being provided), 30% by massof Mn₂O₃ and the balance as aluminum oxide (aluminum oxide:manganeseoxide=100 parts by mass: 45 parts by mass). Catalyst U (9 g) and 30 mlof the solvent (slurry concentration: 30 g/100 ml) were packed in areaction vessel, the catalyst was subjected to hydrogen reduction in thesame manner as in Comparative Example 1, the FT reaction was started bybringing a synthesis gas comprising argon, carbon monoxide and hydrogeninto contact with this catalyst in the same manner as in ComparativeExample 1, and then the FT reaction was carried out by introducingcarbon dioxide. The Ru dispersion of Catalyst U after the reduction was35%. Also, the feeding amount of the synthesis gas yielding a conversionratio of 60% was W/F 5.8 g·hr/mol. After 48 hours from the commencementof the reaction, the chain propagation probability (α) was 0.81, the C₅+selectivity was 72%, the olefin/paraffin ratio in C₃ was 1 or less, andthe C₅+ productivity was 350 g/kg/hr. Also, the FT reaction was carriedout by repeating the same procedure except that introduction of carbondioxide was not carried out. As a result, the chain propagationprobability (α) was 0.85, the C₅+ selectivity was 79%, theolefin/paraffin ratio in C₃ was 1 or less, and the C₅+ productivity was380 g/kg/hr.

Since no sodium compound was provided on the catalyst in this example,each of the chain propagation probability (α), C₅+ selectivity andolefin/paraffin ratio in C₃ was small, and these values were furtherreduced when carbon dioxide coexisted.

COMPARATIVE EXAMPLE 9

The FT reaction was carried out in the same manner as in Example 9,except that the partial pressure of carbon dioxide to be introduced 20hours after commencement of the FT reaction in Example 4 was changed to1.2 MPa. After 48 hours from the commencement of the reaction, the chainpropagation probability (α) was 0.88, the C₅+ selectivity was 81%, theolefin/paraffin ratio in C₃ was 3.5, and the C₅+ productivity was 330g/kg/hr.

Since the amount of carbon dioxide coexisted was too large, the C₅+productivity was low in this example.

The reaction conditions and results in these Examples and ComparativeExamples are shown in Table 1 (Examples) and Table 2 (ComparativeExamples).

TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 <Catalyst> A B C D E (Chemicalcomposition) Ruthenium (% by mass) 1 1.5 10 20 30 Manganese (% by mass)60 50 5 10 30 Metal (% by mass) 0.1 0.2 3 7 10 Metal species of themetal Na Na Na Na Na Alumina (% by mass) Balance Balance Balance BalanceBalance (Physical property) Specific surface area (m²/g) 100 140 300 22060 Bulk density (g/ml) 1.6 1.45 0.8 0.9 1.8 Particle distribution (μm)5-200 5-200 10-180 5-40 5-70 Average particle size (μm) 95 95 90 20 25<Production conditions> (Activation conditions) Temperature (° C.) 140150 220 250 310 Hydrogen partial pressure (MPa · G) 10 6 1 0.5 0.1 Time(hr) 1 0.5 48 24 0.1 Presence of dispersion medium Present PresentAbsent Absent Absent (Production of hydrocarbons) Slurry concentration(g/100 ml) 1 3 35 40 50 H₂/CO ratio 0.6 0.8 2.3 2.5 2.7 Reactiontemperature (° C.) 210 230 280 290 320 H₂—CO pressure (MPa · G) 10 6 1.81.5 1 CO₂/synthesis gas (%) 0 0 0 0 0 <Reaction results> CO conversionratio (%) 60 60 60 60 60 Chain propagation probability (α) 0.92 0.920.89 0.88 0.88 C₅+ selectivity (%) 92 92 82 83 80 Olefin/paraffin ratioin C₃ 4 4 3.8 3.9 3.9 C₅+ productivity (g/kg/hr) 420 380 930 1000 830Ex. 6 Ex. 7 Ex. 8 Ex. 9 <Catalyst> E F G H (Chemical composition)Ruthenium (% by mass) 1 0.5 2 3 Manganese (% by mass) 60 50 50 30 Metal(% by mass) 0.1 0.2 0.5 0.9 Metal species of the metal Ca K Na NaAlumina (% by mass) Balance Balance Balance Balance (Physical property)Specific surface area (m²/g) 100 140 140 165 Bulk density (g/ml) 1.61.45 1.45 1.25 Particle distribution (μm) 5-200 5-200 10-180 20-150Average particle size (μm) 95 95 80 60 Ru dispersion (%) 38 39 33 33<Production conditions> (Activation conditions) Temperature (° C.) 140150 160 170 Hydrogen partial pressure (MPa · G) 10 6 5 2 Time (hr) 1 0.572 4 Presence of dispersion medium Present Present Absent Present(Production of hydrocarbons) Slurry concentration (g/100 ml) 1 3 5 30H₂/CO ratio 0.6 0.8 1 2 Reaction temperature (° C.) 210 230 240 270H₂—CO pressure (MPa · G) 10 6 4.5 2 CO₂/synthesis gas (%) 0 0.5 0 1 0 100 10 <Reaction results> CO conversion ratio (%) 60 60 60 60 60 60 60 60Chain propagation probability (α) 0.92 0.91 0.92 0.91 0.91 0.9 0.9 0.89C₅+ selectivity (%) 92 89 90 88 88 86 85 85 Olefin/paraffin ratio in C₃4 4 4 4 4 3.9 4 3.9 C₅+ productivity (g/kg/hr) 420 435 380 405 420 485500 595 Ex. 10 Ex. 11 Ex. 12 Ex. 13 <Catalyst> J K L M (Chemicalcomposition) Ruthenium (% by mass) 4 10 20 30 Manganese (% by mass) 30 510 30 Metal (% by mass) 0.9 3 7 10 Metal species of the metal Na K Ca CaAlumina (% by mass) Balance Balance Balance Balance (Physical property)Specific surface area (m²/g) 165 300 220 60 Bulk density (g/ml) 1.25 0.80.9 1.8 Particle distribution (μm) 20-125 10-180 5-40 5-70 Averageparticle size (μm) 50 90 20 25 Ru dispersion (%) 30 29 22 18 <Productionconditions> (Activation conditions) Temperature (° C.) 170 220 250 310Hydrogen partial pressure (MPa · G) 2 1 0.5 0.1 Time (hr) 4 48 24 0.1Presence of dispersion medium Present Absent Absent Absent (Productionof hydrocarbons) Slurry concentration (g/100 ml) 30 35 40 50 H₂/CO ratio2 2.3 2.5 2.7 Reaction temperature (° C.) 270 280 300 320 H₂—CO pressure(MPa · G) 2 1.8 1.5 1 CO₂/synthesis gas (%) 0 10 0 50 0 30 0 30<Reaction results> CO conversion ratio (%) 60 60 60 60 60 60 60 60 Chainpropagation probability (α) 0.9 0.89 0.89 0.89 0.88 87 0.88 0.86 C₅+selectivity (%) 85 85 82 81 80 79 80 78 Olefin/paraffin ratio in C₃ 43.9 3.8 3.7 3.9 3.8 3.8 3.6 C₅+ productivity (g/kg/hr) 900 1050 930 10301000 1100 830 930

TABLE 2 Comp. Comp. Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5<Catalyst> O P Q R S (Chemical composition) Ruthenium (% by mass) 3 30.1 40 3 Manganese (% by mass) 30 30 30 30 30 Metal (% by mass) 0.9 0.90.9 0.9 30 Metal species of the metal Na Na Na Na Na Alumina (% by mass)Balance Balance Balance Balance Balance (Physical property) Specificsurface area (m²/g) 55 50 160 160 160 Bulk density (g/ml) 1.8 2 1.25 1.41.25 Particle distribution (μm) 10-150 10-150 10-150 10-150 10-150Average particle size (μm) 80 80 80 80 80 <Production conditions>(Activation conditions) Temperature (° C.) 170 170 170 170 170 Hydrogenpartial pressure (MPa · G) 2 2 2 2 2 Time (hr) 4 4 4 4 4 Presence ofdispersion medium Present Present Present Present Present (Production ofhydrocarbons) Slurry concentration (g/100 ml) 30 30 30 30 30 H₂/CO ratio2 2 2 2 2 Reaction temperature (° C.) 270 270 270 270 270 H₂—CO pressure(MPa · G) 2 2 2 2 2 CO₂/synthesis gas (%) 0 0 0 0 0 <Reaction results>CO conversion ratio (%) 60 60 60 60 60 Chain propagation probability (α)0.9 0.9 0.9 0.9 0.9 C₅+ selectivity (%) 85 85 85 85 85 Olefin/paraffinratio in C₃ 4 4 4 4 4 C₅+ productivity (g/kg/hr) 145 130 80 300 240Comp. Comp. Comp. Comp. Ex. 6 Ex. 7 Ex. 8 Ex. 9 <Catalyst> T U V I(Chemical composition) Ruthenium (% by mass) 3 3 3 3 Manganese (% bymass) 0 Balance 30 30 Metal in metal (% by mass) 0.9 0.9 0 0.9 Metalspecies of the metal Na Na — Na Alumina (% by mass) Balance 0 BalanceBalance (Physical property) Specific surface area (m²/g) 360 40 160 165Bulk density (g/ml) 0.75 2.4 1.25 1.25 Particle distribution (μm) 10-15010-150 10-150 20-150 Average particle size (μ) 80 80 80 60 Ru dispersion(%) 65 14 35 33 <Production conditions> (Activation conditions)Temperature (° C.) 170 170 170 170 Hydrogen partial pressure (MPa · G) 22 2 2 Time (hr) 4 4 4 4 Presence of dispersion medium Present PresentPresent Present (Production of hydrocarbons) Slurry concentration (g/100ml) 30 30 30 30 H₂/CO ratio 2 2 2 2 Reaction temperature (° C.) 270 270270 270 H₂—CO pressure (MPa · G) 2 2 2 2 CO₂/synthesis gas (%) 0 10 0 100 10 60 <Reaction results> CO conversion ratio (%) 60 60 60 60 60 60 60Chain propagation probability (α) 0.8 0.75 0.9 0.89 0.85 0.81 0.88 C₅+selectivity (%) 73 69 85 83 79 72 81 Olefin/paraffin ratio in C₃ 0.5 0.16 5 <1 <0.1 3.5 C₅+ productivity (g/kg/hr) 210 150 150 280 380 350 330

Industrial Applicability

According to the method for producing hydrocarbons of the presentinvention, the FT reaction can be carried out stably and smoothly withhigh chain propagation probability (α), excellent olefin selectivity andC₅+ productivity and high catalytic activity without causing generationof heat spots and the like. Furthermore, the decarbondioxide step forremoving carbon dioxide in a synthesis gas can be simplified or omitted,so that liquid hydrocarbons can be produced efficiently. The method ofthe present invention can greatly contribute to the increased productionof kerosine and gas oil fractions including hydro-cracking of formed waxfractions and dimerization and trimerization of formed olefin.

1. A method for producing hydrocarbons, comprising: (I) subjecting to areduction treatment a catalyst comprising a carrier having providedthereon: 0.1 to 10% by mass of at least one metal selected from analkali metal, an alkaline earth metal, a rare earth metal and the GroupIII in the periodic table based on the catalyst weight, and 1 to 30% bymass of ruthenium based on the catalyst weight, said carrier comprisingan aluminum oxide and a manganese oxide having an average number ofcharges of manganese of exceeding Mn²⁺, and said catalyst having aspecific surface area of from 60 to 350 m²/g and a bulk density of from0.8 to 1.8 g/ml; (II) dispersing the catalyst in liquid hydrocarbons ina concentration of from 1 to 50 w/v %; and (III) bringing the catalystinto contact with a gas mixture comprising hydrogen and carbon monoxideat a pressure of from 1 to 10 MPa, and (i) at a reaction temperature offrom 170 to 300° C. under such conditions that carbon dioxide issubstantially absent, or (ii) at a reaction temperature of from 200 to350° C. under such conditions that carbon dioxide coexists in an amountof from 0.5 to 50% based on the total pressure of the hydrogen and thecarbon monoxide.
 2. The method according to claim 1, wherein ratio ofthe aluminum oxide and manganese oxide on the carrier is from 5 to 160mass parts of the manganese oxide based on 100 mass parts of thealuminum oxide.
 3. The method according to claim 1 or 2, wherein thealuminum oxide in the carrier is neutral alumina or alkaline alumina. 4.The method according to claim 1, wherein the catalyst is dispersed inthe liquid hydrocarbon in a concentration of from 3 to 40 w/v %.
 5. Themethod according to claim 1, wherein the catalyst is dispersed in theliquid hydrocarbon in a concentration of from 5 to 35 w/v %.
 6. Themethod according to claim 1, wherein the (III) bringing the catalystinto contact with a gas mixture comprising hydrogen and carbon dioxideat a pressure of from 1 to 10 MPa is (i) at a reaction temperature offrom 170 to 300° C. under such conditions that carbon dioxide issubstantially absent.
 7. The method according to claim 1, wherein the(III) bringing the catalyst into contact with a gas mixture comprisinghydrogen and carbon dioxide at a pressure of from 1 to 10 MPa is (ii) ata reaction temperature of from 200 to 350° C. under such conditions thatcarbon dioxide coexists in an amount of from 0.5 to 50% based on thetotal pressure of the hydrogen and the carbon monoxide.
 8. The methodaccording to claim 1, wherein the catalyst has a particle sizedistribution of from 5 to 200 μm.
 9. The method according to claim 1,wherein the catalyst has a specific surface area of from 80 to 300 m²/g,a bulk density of from 0.9 to 1.5 g/ml and a particle size distributionof from 5 to 180 μm.
 10. The method according to claim 1, wherein thecatalyst has a specific surface area of from 100 to 250 m²/g, a bulkdensity of from 0.9 to 1.3 g/ml and a particle size distribution of from10 to 150 μm.